1. Field of the Invention
The present invention relates to a blood pump for forcibly circulating blood, which is used in decay of a patient's heart or in an operation thereof.
2. Description of the Related Art
Conventionally, there has been known such a blood pump as shown in FIG. 6. In this blood pump, inclined strip-like long and short blades b and c are alternately and radially formed on the upper surface of a disk-like rotor a, and a cavity d is formed in the rotor a at the position where the base portions of the blades b and c are located.
Additionally, in this figure, reference symbol e indicates a casing; f is a suction port; and g is a discharge port.
In the above conventional blood pump, however, a passage for allowing blood to forcibly flow down to a gap portion between the lower surface of the rotor a and the casing e, and for introducing the blood up to the outer peripheral portion of the rotor a is not formed, and accordingly, when blood or air stagnates at the gap portion, particularly, in the vicinity of the rotating shaft of the rotor a, there occurs solidification of the blood at this portion.
The blood thus solidified is pushed out by the blades, and enters in the body from the discharge port g. This brings about disadvantages in causing the thrombus of the peripheral blood vessels, and in exerting adverse effects on the kidney.